It can be used for queries like this in MySQL: `SELECT * FROM `plans` ORDER BY FIELD(`interval`, 'day', 'week', 'month', 'year');`

OrderByField.php

<?php

namespace App\Traits;

/**
 * Traits that eases the use of ORDER BY FIELD with an eloquent model.
 * https://github.com/laravel/ideas/issues/1066
 */
trait OrderByField
{
    /**
     * Scope orderByField(string $field, array $values).
     *
     * @param \Illuminate\Database\Query\Builder $query
     * @param string $field
     * @param array $values
     * @return \Illuminate\Database\Query\Builder
     */
    public function scopeOrderByField($query, string $field, array $values)
    {
        if (empty($values)) {
            return $query;
        }

        $placeholders = implode(', ', array_fill(0, count($values), '?'));

        return $query->orderByRaw("FIELD({$field}, {$placeholders})", $values);
    }
}

Example:

$plans = Plan::orderByField('interval', ['day', 'week', 'month', 'year'])->get();

laravel/ideas#1066

If you allow user input, this is vulnerable to SQL injections.

public function scopeOrderByField(Builder $query, string $field, array $values)
{
    $placeholders = implode(', ', array_fill(0, count($values), '?'));
    return $query->orderByRaw(DB::raw("FIELD({$field}, {$placeholders})", $values));
}